IC/ID Field Screening and Source Tracing Guidance Manual

Project Background

Municipalities currently use a wide variety of field screening methodologies to identify illicit discharge and illicit connections, with varying levels of success. Some flexibility is required for determining which field screening methodology is the most appropriate given each municipality’s unique program requirements and storm drainage infrastructure. Most municipalities face financial challenges trying to achieve regulatory permit compliance and do not have sufficient resources to analyze other jurisdictions’ methodologies or successes, or to research alternative IDDE (IC/ID) screening methodologies for their specific needs. The purpose of this project was to develop a single, detailed Manual that municipal staff across Washington State can use for field screening their storm drainage systems for illicit discharges and illicit connections based on their specific circumstances.

 As an initial step towards the development of the Manual, a survey of Phase I and II jurisdictions in Washington State and literature review was conducted with the goal of determining which IDDE (IC/ID) field screening methodologies are the most effective, what innovative techniques are currently being used in the United States, and which methodologies should be included in the Manual for use in Washington State. The results from this effort have been compiled in a summary report.

Background on the 2020 manual update

This 2020 IC-ID Manual update was developed by Herrera Environmental Consultants and Aspect Consulting for King County using funding from Western Washington permittees. This update was overseen by the Source ID subgroup of the Stormwater Work Group (SWG) which is part of the Stormwater Action Monitoring (SAM) collaborative. The 2020 IC-ID Manual update was based on a survey of Washington permittees, two feedback/input workshops, a literature review, and a data review.
*The 2020 Manual will be made available March 2020

Workshop Desription

A total of eight hands-on workshops on the 2020 Illicit Connection and Illicit Discharge Field Screening and Source Tracing Guidance Manual (IC-ID Manual) will be offered in Western Washington from April-July 2020. There is no charge for attendees; workshops are funded by the SAM program and municipal permittees.

Workshop objectives

  • Gain an awareness of the key changes in the 2020 IC-ID Manual
  • Participate in engaging hands on exercises for screening and tracing illicit connections and illicit discharges

Workshop target audiences

  • Municipal staff responsible for screening and tracing illicit connections and illicit discharges
  • Municipal NPDES permit coordinators
  • Secondary permittee staff responsible for screening and tracing illicit connections and illicit discharges
  • Workshops are open to all municipal staff with priority given to those based in western Washington

  • workshop dates and locations

    Wednesday, April 22:     City - Renton, WA     Time - 9am-1pm     
    Building - Maintenance Shops (3555 NE 2nd St)      Room - Training Room

    Tuesday, April 28:     City - Mount Vernon, WA     Time - 9am-1pm     
    Building - Police Campus (1805 Continental Place)      Room - Training Room

    Tuesday, May 5:     City - Edmonds, WA     Time - 9am-1pm     
    Building - City Hall (121 5th Ave N)      Room - Brackett Room

    Tuesday, May 12:     City - Tumwater/Olympia, WA     Time - 9am-1pm     
    Building - Thurston County Emergency Management Center (9521 Tilley Rd SW)      
    Room - Training Room

    Wednesday, May 20:     City - Poulsbo, WA     Time - 9am-1pm     
    Building - City Hall (200 Moe St NE)      Room - Council Chambers

    Thursday, June 4:     City - Vancouver, WA     Time - 9am-1pm     
    Building - City Hall (415 W 6th St)      Room - Aspen Room

    Tuesday, June 23:     City - Bellevue, WA     Time - 9am-1pm     
    Building - Aaron Education Center at the Bellevue Botanical Garden (12001 Main St)    
    Room - Aaron Room

    Wednesday, July 1:     City - Seattle, WA     Time - 12:30 pm-4:30 pm    
    Building - King Street Center (201 S Jackson St)      Room - 8th Floor Conference Room


    IC/ID Manual (pdf)

    IC/ID Manual (Word file) - NOTE file is 50 MB

    Appendix B - Example Field Forms
      Appendix B - King County WQ Sampling Data Sheet
      IC/ID Field Screening Survey Results and Literature Review

     Illicit Discharge Indicator Thresholds Memorandum


    Training Presentations

    Guidance Manual Training - PDF of Powerpoint Presentation (May 2013)